A geographical and environmental analysis of Lyme disease

by 1977- Trotter, Sharon Lynn

Abstract (Summary)

This research demonstrates that August followed by July are the peak months for
Lyme disease reports (1991 to 2000) across the 48 contiguous United States. Eight states
have a secondary peak in December. For eleven states disease reports increased, two
decreased and 34 had no trend (1991 to 2000). Greatest increases occurred in
northeastern states, where the disease is already endemic. Climatic variables in the three
months (April, May, June) prior to the summer peak have strong relationships with
disease reports/rates. Ninety percent of all cases occur in counties with an average
temperature in April, May, June between 10.99 and 17.92°C, soil moisture surplus values
of 3.43 to 11.00 centimeters, and precipitation values of 23.57 to 33.45 centimeters. The
disease system appears to be constrained more by moisture than temperature. The
predictive “climatic envelope” model was used to produce a risk map for Lyme disease.